QT 创建本地数据库(SQLite数据库)存储数据

注意：QT自带SQLITE数据库,不需要再安装

1.创建一个包含创建、查询、修改和删除数据库的数据库类(DataBase)

DataBase.h头文件

#pragma once

#include <QObject>

#include <QtSql/QSqlDatabase>

#include <QtSql/QSqlQuery>

#include <QtSql/QSqlDriver>

#include <QtSql/QSqlError>

#include "client_global.h"

struct StudentData
{
　　QString name;
　　int score;
　　QString grade;
};

class DataBase : public QObject

{

    Q_OBJECT

public:

    DataBase(QString name,QObject *parent=);

    ~DataBase();


public:

    bool insertData(StudentData data);

    bool deleteData(int name);

    bool getDataByName(int name, StudentData & data);

    bool getDataList(QList<StudentData> & list);
　　 bool update();

private:

    QSqlDatabase m_DataBase;

private:

    bool initTable();

    bool isExistTable(QString table);

    bool createTable(QString table);

};

DataBase.cpp源文件

#include "XDataBase.h"

#include <QCoreApplication>

#include <QDebug>

#include <QSqlRecord>

DataBase::DataBase(QString name, QObject *parent)

    : QObject(parent)

{

    if (QSqlDatabase::contains(name)) {

        m_DataBase = QSqlDatabase::database(name);

    }

    else {

        m_DataBase = QSqlDatabase::addDatabase("QSQLITE");

        m_DataBase.setDatabaseName(name+".db");

        m_DataBase.setDatabaseName(QCoreApplication::applicationDirPath()+"//"+ name);

    }

    initTable();

}

DataBase::~DataBase()

{

}

bool DataBase::initTable()

{

    if (!m_DataBase.open()) {

        return false;

    }

    if (!isExistTable("students")) {

        createTable("students");

    }

    return false;

}

bool DataBase::isExistTable(QString table)

{

    bool bRet = false;

    if (!m_DataBase.open()) {

        return bRet;

    }

    QSqlQuery query(m_DataBase);

    query.exec(QString("select count(*) from sqlite_master where type='table' and name='%1'").arg(table));    //关键的判断

    if (query.next())

    {

        if (query.value().toInt() > )

        {

            bRet = true;

        }

    }

    return false;

}

bool DataBase::createTable(QString table)

{

    if (!m_DataBase.open()) {

        return false;

    }

    QSqlQuery query(m_DataBase);

    if (table == QString("students")) {

        bool success = query.exec("CREATE TABLE students ("

                                    "id INTEGER PRIMARY KEY AUTOINCREMENT, "

                                    "name VARCHAR(40) NOT NULL, "

                                    "score INTEGER NOT NULL, "

                                    "grade VARCHAR(40) NOT NULL)");

        if (success) {

            return true;   //新建数据库成功

        }

        else {

            QSqlError lastError = query.lastError();

            QString err = lastError.driverText();

            return false;

        }

    }

    else {

        return false;

    }

}

bool DataBase::insertData(StudentData data)

{

    if (!m_DataBase.open()) {

        return false;

    }

    QSqlQuery query(m_DataBase);

    bool success = query.exec(QString("INSERT INTO students (name, score,class) "

        "VALUES (%1, %2, %3)").arg(data.name)

                              .arg(data.score)

                              .arg(data.grade));

    if (!success) {

        QSqlError lastError = query.lastError();

        QString err = lastError.driverText();

        return false;

    }

    return true;

}

bool DataBase::deleteData(QString name)

{

    if (!m_DataBase.open()) {

        return false;

    }

    QSqlQuery query(m_DataBase);

    query.prepare(QString("DELETE FROM students WHERE name='%1'").arg(name));

    query.exec();

    return false;

}

bool DataBase::getDataByName(int name, StudentData & data)

{

    if (!m_DataBase.open()) {

        return false;

    }

    QSqlQuery query(m_DataBase);

    query.prepare(QString("SELECT * FROM students WHERE name='%1'").arg(name));

    query.exec();

    QSqlRecord rec = query.record();

    if (query.next())

    {

        data.name = query.value().toString();

        data.score = query.value().toInt();

        data.grade = query.value().toString();

        return true;

    }

    return false;

}

bool DataBase::getDataList(QList<StudentData>& list)

{

    if (!m_DataBase.open()) {

        return false;

    }

    QSqlQuery query(m_DataBase);

    query.prepare(QString("SELECT * FROM students"));

    query.exec();

    QSqlRecord rec = query.record();

    while (query.next())

    {

        StudentData data;

        device.name = query.value().toInt();

        device.score = query.value().toString();

        device.grade = query.value().toInt();

        list.append(data);

        return true;

    }

    return false;

}

bool DataBase::update()

{

    if (!m_DataBase.open()) {

        return false;

    }

    QSqlQuery query(m_DataBase);

    query.prepare("UPDATE students SET score = 100 , name = '小A'");

    query.exec();

    return false;

}

调用：

XClientApp.h头文件

#pragma once

#include <QApplication>

#include <DataBase.h>

#include "ServerAPI.h"

#define clientApp static_cast<XClientApp*>(QCoreApplication::instance())

class XClientApp : public QApplication

{

    Q_OBJECT

public:

    XClientApp(int argc, char *argv[]);

    ~XClientApp();

    DataBase* getDataBase();

    ServerAPI* getServerAPI();

    QString getAppName();

private:

    void setFont(QString font);

    void setStyle();

private:

    DataBase* m_pDataBase;

    ServerAPI* m_pServerAPI;

signals:

    void sglSystemMessage(QString type, QString data);

};

XClientApp.cpp源文件

#include "XClientApp.h"

XClientApp::XClientApp(int argc, char *argv[])

    : QApplication(argc, argv)

{

     m_pDataBase = new DataBase("xclient", this);

     setWindowIcon(QIcon(":/Images/Resources/朱砂古镇.ico"));//可执行程序图标

     setStyle();

     m_pServerAPI = new ServerAPI(this);   //注意有重载

}

DataBase * XClientApp::getDataBase()   //获取本地数据库并进行操作

{

    return m_pDataBase;

}

巴特西

QT 创建本地数据库(SQLite数据库)存储数据

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